Endoscopic procedures have become more and more common. A host of specialty instruments designed for endoscopic procedures have been developed. These instruments typically are elongated and controlled at their proximal end by the surgeon. Remotely, at the distal end, can be mounted a variety of different instrument assemblies to facilitate such activities as cutting, gripping, or cauterizing, to name a few. Common in many such instruments is an elongated housing or stem, with some operating mechanism, such as a rod or a wire, extending therethrough to the distal end of the instrument. Frequently at the distal end, the annular space between the housing or stem and the operating mechanism leaves portions exposed where blood or tissue can migrate into the annular space. This is undesirable since endoscopic tools are reused, perhaps several times in the same day on different patients. It is desirable to be able to completely sterilize these instruments between procedures. This includes getting into the annular space between the housing or stem and the rod or other device that extends therethrough. At the same time it is desirable to have the instrument be as compact and lightweight as possible to facilitate placement of the distal end within the body and to minimize fatigue for the surgeon handling the instrument at the proximal end. Many times during a procedure, the instrument must be rotated about its own axis for better placement. Accordingly, it is not only desirable to have a lightweight structure, but also a mechanism for rapidly changing the orientation of the assembly at the distal end to facilitate the endoscopic procedure. At the same time, the instrument must be constructed in a manner that does not allow the gasses typically used in endoscopic procedures, such as carbon dioxide, to escape from the area being worked on, thus obstructing the surgeon's view. In the past, bulky arthroscopic cannulas with fluid passages have been designed such as shown in U.S. Pat. No. 5,037,386. Instruments have been designed with means to add an irrigating fluid such as shown in U.S. Pat. No. 4,754,077. Other diagnostic devices have been fairly bulky and provide for injection of a fluid or a gas during operating. Such a device is illustrated in U.S. Pat. No. 4,598,698. Flexible biopsy forceps, with a cleaning port for introducing cleansing fluid, are illustrated in U.S. Pat. No. 4,646,751. U.S. Pat. No. 2,691,370 illustrates an instrument for heart surgery involving a telescope therein with means for flushing the front lens of the telescope during heart surgery.